Data management system, data processing system, and computer-readable medium having on which data management program is recorded

ABSTRACT

A data management system including a storage and activating an application so that the application accesses contents in the storage and processes the contents. The data management system also monitors access of the application to the contents by associating information for the application brought into an activated status with information for the accessed contents. The data management system also enciphers the contents with the application information when the activated application writes the contents into the storage while deciphering the contents with the application information when the activated application reads out the contents.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of application Ser. No.10/092,794, filed Mar. 8, 2002, now U.S. Pat. No. 7,350,084, it beingfurther noted that foreign priority benefit is based on Japanese PatentApplication No. 2001-327302 filed Oct. 25, 2001, the disclosures ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technology for protecting copyrightsof various types of digital contents when the copyrights of such digitalcontents are executed in a system which is composed of a recordingreproducing apparatus such as a hard disk recorder, a data processingsystem such as a personal computer and so on.

2. Description of the Related Art

Recently, technologies for digitizing information is developed, storageunits for storing information therein tend to become large in capacity,and broadband networks are widely deployed. With this tendency, contentscontaining video data (moving picture data), audio data, image data andso on tend to be formed into digital information and stored in varioustypes of recording media such as storage units, rewritable media and soon.

However, when such technology development makes it easy for a user toeffect data conversion from one type into another one, with intention orwithout intention, the user tends to distribute or transfer the datawithout license of the copyright holder of the contents, with the resultthat copyrights will often suffer from risk of infringement.

For this reason, in order to protect copyrights of the contents,technologies for enciphering such copyright materials have beendeveloped so far. When such technologies are introduced into a situationwhere the copyright materials are handled with a data management system,encryption data (hereinafter referred to as enciphered data) becomesmeaningless unless a key for deciphering the ciphertext is obtained.Therefore, it follows that the encryption system is effective forprotecting copyrights.

However, when an application software (hereinafter simply referred to asapplication) is activated to access the enciphered data for utilizingthe data, it becomes necessary to decipher the enciphered data and storethe same in a recording medium. In this way, when the data is oncedeciphered to be a plaintext and the resulting plaintext is stored inthe recording medium, the user becomes allowed to carry out anyoperation such as transferring, copying, falsification and so on. Thus,there can be a concern that the copyright protection does not functionin this situation.

In order to cope with this situation, there has been proposed atechnology which is disclosed in Japanese Patent laid-open gazette No.2000-311114, No. 2000-330870 or the like.

According to the technology disclosed in the gazettes, when a rewritablemedium is utilized, a media ID (Identification) inherent to the mediumis utilized as the encryption key. As for a medium having no media ID,an encryption key written in a read-in region, an exchange processingregion, a ROM (Read Only Memory) which a file system is ordinarilyprohibited to access, is utilized. As for a medium having no particularROM region such as a hard disk drive or the like, a device ID involvedin a BIOS (Basic Input Output System) in a concealing manner is utilizedas the encryption key. According to the technology disclosed in theaforesaid gazette, data enciphered with these types of encryption keysis stored in a medium, whereby the copyright protection is madeeffective.

Meanwhile, if a storage medium containing an enciphered copyrightmaterial (contents) is additionally attached to a personal computer,data recording reproducing apparatus or the like which is operatedwithout copyright protection function, a situation can be brought aboutin which a storage medium with no encryption function (hard disk forstoring data of no necessity in undergoing encryption processing) and astorage medium with encryption function (hard disk designed for storingencrypted data) are operated in a mixed fashion.

Under this situation, if an application is activated to read theenciphered data and utilize the same, the data of copyright materialreleased from enciphered status can be wholly or partly read, with theresult that the data of copyright material can be transferred from oneperson to another without regulation. The aforesaid conventionaltechnology does not mention any countermeasure against the situationwhere the material can suffer from copyright infringement.

For example, an assumption is introduced that when an editingapplication is activated to change the data, the data in the halfway ofprocessing stage may be temporarily stored in a file or a memory file.In this case, the temporary stored file having contents meaningful as acopyright material is created in a medium other than a medium as anobject of encryption. That is, data having not undergone encipheringprocess is stored in the file or the memory file. At this time, if asystem for protecting copyrights is tried to be built by using anexisting file system, then a converting work is requested, i.e., alldata stored in the hard disk are enciphered. However, if such systemwere built, even the copyright holder or a person licensed by thecopyright holder can be stringently restricted upon executing thecopyrights. Therefore, the copyrights cannot be executed in a reasonablemanner.

SUMMARY OF THE INVENTION

The present invention is made in view of the above aspect. Therefore, itis an object of the present invention to provide a system which canreliably protect a copyright of contents of a deciphered version withoutunreasonably restricting the execution of the copyright even if astorage medium having no encryption function and a storage medium havingan encryption function are placed under processing in a mixed fashion.

According to the present invention, in order to attain the above object,there is provided a data management system including a storage mediumfor storing contents, application executing means for activating anapplication so that the application accesses the contents stored in thestorage medium and effects a processing on the contents, accessmonitoring means for monitoring the status of access of the applicationto the contents by associating inherent information for the applicationbrought into an activated status by the application executing means,with inherent information for the contents accessed by the application,and filtering means for enciphering the contents with the inherentinformation for the application when the application under the activatedstatus writes the contents into the storage medium while deciphering thecontents with the inherent information for the application when theapplication under the activated status reads out the contents from thestorage medium.

The data management system as set forth above may be further arranged toinclude an operating system as a software for controlling the executionof the application, the operating system assigning identificationinformation to each process upon executing the application by theapplication executing means, wherein the access monitoring meansutilizes the identification information as the inherent information forthe application.

The data management system as set forth above may be further arranged insuch a manner that the access monitoring means registers the inherentinformation for the application and the inherent information for thecontents in a management table so that the inherent information for theapplication and the inherent information for the contents are associatedwith each other, and that the access monitoring means monitors thestatus of access with the assistance of the management table.

In this case, the data management system may be further arranged in sucha manner that at least one piece of logical drive is built in thestorage medium and the contents is reserved in the logical drive, a filesystem for managing the logical drive is built in each of the logicaldrive, and at least one file system is arranged to serve as anencryption file system which has a cryptographic attribute determinedfor each file or folder containing the contents, enciphers the contentsat each file or folder upon storing the contents in the storage medium.Alternatively, the data management system may be further arranged tohave an encryption file system which enciphers the file system as awhole upon storing the contents in the storage medium.

Further, according to the present invention, there is provided a dataprocessing apparatus arranged to include the application executingmeans, the access monitoring means, and the filtering means, each ofwhich being described above.

Furthermore, according to the present invention, there is provided arecording medium capable of being read by a computer having recordedthereon a data management program which forces the computer to realize afunction for protecting a copyright of contents stored in a storagemedium when an application accesses the contents to effect a processingon the contents, wherein the data management program forces the computerto function as the access monitoring means and the filtering means.

As described above, according to the present invention, when anapplication accesses the contents stored in the storage medium, thestatus of access is monitored at each application (process). Thus, thecontents read and utilized by the application are enciphered and/ordeciphered by using the inherent information of the application.

According to the above arrangement, even if the user is placed under anenvironment where the storage medium having no encryption function andthe storage medium having an encryption function are utilized in a mixedfashion, and the user drives the data management system in such a mannerthat the application reads the enciphered contents stored in the storagemedium having an encryption function and temporarily stores the contentsin the storage medium having no encryption function, the followingadvantages can be obtained. That is, the copyright concerning thematerial can be comfortably utilized by an authorized user, i.e., thecopyright can be free from unreasonable restriction, the copyright ofthe contents released from encryption can be reliably protected, andgreat contribution can be expected to the performance improvement in thedata management system.

In other words, when digitized copyright material data (digitalcontents) is stored in a storage medium, the digitized copyrightmaterial data is once enciphered and thereafter stored in the storagemedium. Therefore, the copyright of the material data can be effectivelyprotected from a copyright violation which can be brought about when theuser unintentionally transfers the copyright material data to a thirdparty who is unauthorized in executing the copyright. Moreover, if amalicious person tries to detach the storage medium from the system andopen the file containing the copyright material data, this person willsurely fail in obtaining meaningful data because the data arefundamentally composed of a ciphertext. Thus, the copyright of thematerial data is effectively protected from infringement.

In this case, one of recommendable arrangements is that dynamicallydetermined information such as identification information given to eachprocess (process ID) assigned by the operating system is utilized asinherent information for the application, and this information isutilized for enciphering the contents. With this arrangement, even ifthe application identical to the application activated upon encipheringthe contents is activated for deciphering the contents, the contentswill be resistant to the deciphering process because of the differencein timing of activation. Accordingly, data deciphered by means of thefile created in the storage medium will not go into a transactionprocess with ease, with the result that the copyright can be morereliably protected from violation.

Further, the data management system is arranged so that the filteringmeans is switched from the valid mode to the invalid mode in itsoperation only when the user authentication is successfully carried out,and the copyright holder himself or herself or a person licensed by thecopyright holder (e.g., a person creating a secondary copyright materialby editing the original material) are registered in advance in the datamanagement system. With this arrangement, the copyright holder himselfor herself or the person licensed by the copyright holder can make thefiltering means invalid in its operation. Thus, the editing work or thelike will not suffer from unreasonable restriction, the copyright willbe free from restriction upon executing the copyright, with the resultthat it becomes possible to avoid copyright infringement.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages will become apparent and morereadily appreciated from the following description of the embodiments,taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram showing an arrangement of a data managementsystem as a first embodiment of the present invention;

FIG. 2 is a flowchart for explaining a processing procedure of an accessmonitoring module employed in the data management system as the firstembodiment;

FIG. 3 is a flowchart for explaining a processing procedure of afiltering module employed in the data management system as the firstembodiment;

FIG. 4 is a block diagram showing an arrangement of a modification ofthe data management system as the first embodiment;

FIG. 5 is a block diagram showing an arrangement of a data managementsystem as a second embodiment of the present invention;

FIG. 6 is a block diagram showing an arrangement of a data managementsystem as a third embodiment of the present invention; and

FIG. 7 is a diagram for explaining a scheme of exclusive controleffected in the data management system as the third embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be hereinafter described withreference to the attached drawings.

FIG. 1 is a block diagram showing an arrangement of a data managementsystem as a first embodiment of the present invention. As shown in FIG.1, the data management system of the first embodiment is built in ageneral-purpose personal computer (data processing apparatus), forexample. The data management system is arranged to include a storageunit 10, an encryption file system 11, a storage unit 20, a file system21, a host file system 30, an application executing module 40, anoperating system 50, an access monitoring module 60, a filtering module70, an authenticating module 71, and a switching module 72.

The data management system of the first embodiment is provided with twosets of storage units 10 and 20, and each of the storage units 10 and 20has a single set of logical drive built therein. In the example shown inFIG. 1, the logical drives built in the storage units 10 and 20 havedrive names of #S0 and #S1, respectively.

The storage unit 10 is a unit for functioning as a first storage unit(storage medium having an encryption function) containing a logicaldrive managed by the encryption file system 11 which will be describedlater on. The encryption file system 11 has a cryptographic attributedetermined for each file or folder containing the contents, enciphersthe contents at each file or folder upon storing the contents (copyrightmaterial file) in the storage unit 10. Alternatively, the encryptionfile system 11 enciphers the file system as a whole upon storing thecontents (copyright material file) in the storage 10.

Accordingly, when data is written in the logical drive of the storageunit 10, the data is enciphered by the encryption file system 11 andthereafter written in the storage unit 10. On the other hand, when datais read from the logical drive of the storage unit 10, the enciphereddata is deciphered by the encryption file system 11 and thereafter readfrom the storage unit 10. Meanwhile, the example shown in FIG. 1 has astatus in which two copyright material files (the file name thereof are#D0 and #D1, respectively) of a ciphertext version are stored in thestorage unit 10.

The storage unit 20 is a unit for functioning as a second storage unit(storage medium having no encryption function) in which there are storedthe contents enciphered by the filtering module 70 which will bedescribed later on. The logical drive built in the storage unit 20 ismanaged by the file system 21 such as of a FAT (File Allocation Table)or the like. In the example shown in FIG. 1, four files (the file namesthereof are #F1 to #F4, respectively) of a ciphertext version and twofiles (the file names thereof are #F5 and #F6, respectively) of aplaintext version are stored in the storage unit 20.

The host file system 30 is a unit for managing both of the encryptionfile system 11 and the file system 21. The host file system 30 isprovided between these file systems 11 and 21 and the filtering module70 which will be described later on.

The application executing module (application executing means) 40 is aunit for activating an application so that the application accesses thecontents stored in the storage units 10 and 20 and effects processing onthe contents.

The operating system 50 is a software for controlling the execution ofthe application. The operating system 50 of the present embodiment isdesigned to handle a plurality of tasks in a multiprocessing manner.That is, when the application execution module 40 activates theapplication, the operating system 50 attaches identification information(process ID) to each process, whereby an application can be called byusing the process ID, or a proper API (Application Program Interface) ofthe file system 11 and 21 can be called depending on the storage units10 and 20 when the application calls the file systems 11 and 21.

In the example shown in FIG. 1, process IDs #A0 and #A1 are assigned totwo processes executed by the application which is activated foraccessing the copyright material stored in the storage unit 10 whileprocess ID of #A2 is assigned to a process executed by an applicationwhich is activated without accessing the copyright material stored inthe storage unit 10. These processes #A0 to #A2 may be executed by notonly a single set of application but also applications different fromone another.

The application may be designed to be operated on a general-use personalcomputer. Thus, the application need not be specifically designed foruse in the data management system of the present invention. An editingsoftware, the Web-browser and so on can be named as an example of suchkind of application. When the application is executed by the applicationexecuting module 40, an operation of each application are managed by theoperating system 50 as a process.

The access monitoring module (access monitoring means) 60 is a modulefor registering inherent information for the application operated by theapplication executing module 40 and inherent information for thecontents, which each of the applications (each process) accesses, in amanagement table (list) 61, so that the inherent information for theapplication and the inherent information for the contents are associatedwith each other. Further, the access monitoring module 60 utilizes themanagement table 61 for monitoring the status of access to the contentsby each application.

At this time, according to the present embodiment, a process ID assignedfrom the operating system 50 to each process is utilized as the inherentinformation for the application, and a file name of a copyright materialfile containing the contents or a drive name of a logical drivecontaining the copyright material file is utilized as the inherentinformation for the contents (see Function (1) which will be describedlater on).

When the application executing module 40 completes the execution of theapplication (process), the access monitoring module 60 deletes theinherent information for the application (process ID) and the inherentinformation for the contents (file name) corresponding to theapplication in the management table 61.

The access monitoring module 60 monitors how the application accessesthe file, creates a list (management table 61) of the file names of thecopyright material as a target of file access each time the application(process) makes access to the material, and memorizes the file nameuntil the process of the application is completed. In particular, whenthe operating system 50 assigns a process ID to the application, theaccess monitoring module 60 registers and memorizes this process ID inthe list as inherent information of the application (process).

The access monitoring module 60 of the present embodiment may bearranged to have the following functions (1) to (5).

Function (1): Function that when the application reads the copyrightmaterial file (contents) stored in the storage 10 (logical drive #S0)managed by the encryption file system 11, the access monitoring module60 registers the file name of the copyright material file containing thecontents read by the application in the management table 61 as theinherent information for the contents. The file name to be registered inthe table contains a drive name of the logical drive in which thecontents read out by the application is stored.

Function (2): Function that when the application effects a processing onthe contents to create a new file, then the access monitoring module 60registers a file name generated for the new file in the management table61 so that the file name and the inherent information (process ID) forthe application are associated with each other. At this time, the accessmonitoring module 60 may change the file name of the new file partly orwholly, and register the changed name in the management table 61. Thefile name utilized in this case is composed of a series of characterscontaining the drive name of the logical drive in which the file isstored. The part of the character series indicating the drive name maybe changed so as to change the destination medium (storages 10 and 20)in which the file is stored. Also, the part of the character series maybe changed so that the file is temporarily stored in a primary storagemeans (storage medium; not shown) as a memory file. Further, a file nameof a copyright material file read out from the encryption file system 11(storage 10) may be registered and memorized as the file name of the newfile.

Function (3): Function that the access monitoring module 60 compares adrive name of the logical drive as a destination for storing a file,which is newly created when the application effects a processing on thecontents, with a drive name (drive name contained in the file name) ofthe logical drive registered in the management table 61 owing toFunction (1), and if it is determined that both of the drive namesdisagree with each other as the result of comparison, then the accessmonitoring module 60 changes a file name of the newly created file sothat the newly created file is stored in the logical drive of the drivename registered in the management table 61 and registers the changedfile name in the management table 61. That is, if there is differencebetween the logical drive in which the newly created file is to bestored and the logical drive in which the contents (copyright materialfile) has been stored, the file name is changed so that the new file iscreated at the same logical drive (the same storage 10) and registrationis made in the management table 61. With this Function (3), the newlycreated file can be created and stored at the same logical drive (samestorage unit 10) as that of the original contents. Thus, the filecreated based on the contents read out from the storage unit 10 havingthe encryption function is once enciphered by the encryption file system11 and thereafter written into the storage unit 10.

Function (4): Function that the access monitoring module 60 compares adrive name of the logical drive as a destination for storing a file,which is newly created when the application effects a processing on thecontents, with a drive name (drive name contained in the file name) ofthe logical drive registered in the management table 61 owing toFunction (1), and if it is determined that both of the drive names arecoincident with each other as the result of comparison, then the accessmonitoring module 60 prohibits a file name of the newly created filefrom being registered in the management table 61. That is, if thelogical drive as the destination for storing the newly created file iscoincident with the logical drive in which the contents (copyrightmaterial file) is stored, it is reliably expected that the newly createdfile is subjected to an enciphering process in the encryption filesystem 11 and then written into the storage unit 10 without undergoingthe enciphering process in the filtering module 70, which will bedescribed later on, in advance. Therefore, according to the presentembodiment, when it is determined that both of the drive names arecoincident with each other, the file name of the newly created file isprohibited from being registered in the management table 61 so that thefile name can be protected from being registered or memorized in thetable, whereby the filtering module 70 becomes free from uselessenciphering operation.

Function (5): Function that the access monitoring module 60 compares adrive name of the logical drive as a destination for storing a file,which is newly created when the application effects a processing on thecontents, with a drive name (drive name contained in the file name) ofthe logical drive registered in the management table 61 owing toFunction (1), and if it is determined that both of the drive namesdisagree with each other as the result of comparison, then as will bedescribed later on the file newly created by the filtering module 70 isonce enciphered and thereafter the resultant enciphered version of thenewly created file is stored in the logical drive (storage 11) as thedestination for storing the file. That is, if there is differencebetween the logical drive in which the newly created file is to bestored and the logical drive in which the contents (copyright materialfile) has been stored, then the operation of the filtering module 70 isvalidated. At this time, by using the above-described Function (2), thefile name may be changed partly or wholly and registered in themanagement table 61 so that the filtering module 70, which will bedescribed later on, temporarily stores the enciphered version of thenewly created file as a memory file in the primary storage means insteadof the logical drive as the storage destination.

Owing to the above-described function of the access monitoring module60, the management table 61 shown in FIG. 1 comes to have registeredidentification information #A0 and #A1 of two processes effected by theapplication which is activated to access the copyright material in thestorage unit 10. As for the process #A0, a file name #D0 (containing alogical drive name #S0) of the copyright material file accessed by theprocess #A0 is registered in the management table 61. Also, the process#A0 creates and develops a couple of new files $file#F1 and $file#F2based on the copyright material file #D0, and the names of the files,i.e., $file#F1 and $file#F2, are registered in the management table 61.Similarly, as for the process #A1, a file name #D1 (containing a logicaldrive name #S0) of the copyright material file accessed by the process#A1 is registered in the management table 61. Also, the process #A1creates and develops a couple of new files $file#F3 and $file#F4 basedon the copyright material file #D1, and the names of the files, i.e.,$file#F3 and $file#F4, are registered in the management table 61.

The files $file#F1 and $file#F2 are enciphered by the filtering module70 which will be described later on, and stored in the storage unit 20having no encryption function through the file system 21.

A processing procedure of the access monitoring module 60 will bedescribed later on with reference to FIG. 2.

The filtering module (filtering means) 70 referrers to the managementtable 61 created by the access monitoring module 60. When theapplication is activated and the process is effected so that datacontaining the contents are written in a file which is newly created inthe storage unit 20 having no encryption function, the filtering module70 enciphers the data containing the contents (file) with inherentinformation for the application, i.e., an encryption key created basedon the process ID. Conversely, when the activated application (process)is effected so that the data enciphered in a manner as described aboveare read out from the file stored in the storage unit 20 having noencryption function, the filtering module 70 deciphers the data(contents) with the encryption key created in the above-describedmanner.

If an enciphered file is simply moved from one storage unit to anotherstorage unit, the filtering module 70 does not execute the encipheringprocessing or deciphering processing.

Further, the processing sequence of the filtering module 70 will bedescribed later on with reference to FIG. 3.

Furthermore, the filtering module 70 is provided with a authenticatingmodule 71 and a switching module 72. Thereby, in order to solve anydisadvantages upon operating the system, a user can enter a password asdescribed below so that the user is authorized and allowed to switch themode of operation (processing of enciphering and/or deciphering) of thefiltering module 70 between a valid mode and an invalid mode.

The authenticating module (authenticating means) 71 is a unit forcarrying out authentication on a user. That is, the authenticatingmodule 71 compares a password entered by the user with a passwordregistered in advance. If they are coincident with each other, then theuser having entered the password is authorized.

The switching module (switching means) 72 is a unit for switching themode of operation of the filtering module 71 between a valid mode and aninvalid mode only when the authenticating module 71 successfully carriesout the authentication on the user.

The above-described application executing module 40, access monitoringmodule 60, filtering module 70, authenticating module 71 and switchingmodule 72 can be realized by a specifically developed software (datamanagement program).

The data management program may be provided in a style of recordingmedium such as a flexible disk, a CD-ROM and so on which can be read bya computer. In the present embodiment, the data management program isstored in advance in a ROM (Read Only Memory; not illustrated) unit of ageneral-purpose personal computer (data processing apparatus). This datamanagement program is read by a CPU (computer; not illustrated) of thegeneral-purpose personal computer (data processing apparatus) andexecuted, whereby functions of the above-described application executingmodule 40, access monitoring module 60, filtering module 70,authenticating module 71 and switching module 72 can be realized.

The data management program may be recorded in a recording unit(recording medium) such as a magnetic disk, an optical disk, amagneto-optical disk and so on, and provided from the recording unit tothe computer through of a communication path.

The above-described storage units 10, 20 are realized by a RAM (RandomAccess Memory; not illustrated) built in a computer serving as ageneral-purpose personal computer (data processing apparatus).Alternatively, the storage units 10, 20 may be realized by a memory unitsuch as a hard disk drive unit (or a memory unit additionally attachedoutside the computer).

The operation of the data management system of the first embodimentarranged as described above will be hereinafter described with referenceto FIGS. 2 and 3.

Initially, the processing sequence of the access monitoring module 60 ofthe data management system of the first embodiment will be describedwith reference to the flowchart (steps S11 to S22) shown in FIG. 2.

The task imposed on the access monitoring module 60 is to avoid such anevent that the copyright material data and a part thereof, which aredecoded for the sake of the processing of the application, are saved inthe storage unit 20 with the data of a plaintext version left notenciphered. To this end, a list of data to be enciphered (managementtable 61) is created.

The operation therefor will be described with reference to the flowchartshown in FIG. 2. The access monitoring module 60 carries out an initialsetting (step S11) and then determines whether or not the application(process) calls a function (Call) for the operating system 50 (stepS12). If it is determined that the function call is made (YES route atstep S12), then it is examined whether the target function of thecalling operation is a read function or not (step S13).

If it is determined that the target function is a read function (YESroute at step S13), the cryptographic attribute of the file as a readingtarget is acquired (step S14). Thereafter, it is examined whether thefile is an enciphered copyright material data (copyright material file)or not (step S15). If it is determined that the file is copyrightmaterial data (YES route at step S15), inherent information for theapplication (i.e., process ID assigned by the operating system 50) and afile name of the copyright material data (containing a logical drivename) are registered in the registration table 61 (step S16). At thistime, the above-described Function (1) is utilized. Thereafter, thefunction call (Call) is made for the operating system 50 (step S17) andthe processing returns to step S12.

If it is determined that the function as the target of calling operation(Call) is not a read function (NO route at step S13), or alternatively,if the file as the target of reading is not copyright material data butany material unnecessary to be enciphered (NO route at step S15), theprocessing immediately goes to step S17.

On the other hand, if the application (process) does not effect functioncall for the operating system 50 (NO route at step S12), then it isexamined whether a return for an open function is performed from theoperating system 50 to the application as a target of registration ornot and whether the file is successfully opened or not (step S18).

If the return for the open function is performed and the file issuccessfully opened (YES route at step S18), then the drive name of thelogical drive in which the file is saved (logical drive as a destinationof storage) is acquired (step S19). Then, it is examined whether or notthe drive name is coincident with a drive name registered in themanagement table 61 of which the logical drive as a destination ofstorage has the copyright material data (copyright material file) storedtherein. That is, it is examined whether the logical drive as thestorage destination of the file is coincident with the logical drive asthe storage destination of the copyright material data (step S20).

If it is determined that the storage destination of the file isdifferent from the logical drive as the storage destination of thecopyright material data (NO route at step S20), then the name of theopened file is registered in the management table 61 so that the filename is associated with the inherent information of the application as atarget of registration (process ID assigned by the operating system 50).At this time, the above-described Functions (2) and (5) are utilized.Thereafter, the processing returns to the open function for theapplication as a target of registration (step S22), and the processingreturns to step S12.

If the return for the open function is not performed or the processingfails to open the file (NO route of step S18), the processingimmediately goes to step S22. Further, even if it is determined that thelogical drive as the storage destination of the file is coincident withthe logical drive as the storage destination of the copyright materialdata (YES route of step S20), the registration at step S21 is notcarried out and the processing immediately goes to step S22 by a reasonwhich will be described later on. At this time, the above-describedFunction (4) is utilized. At step S21, the above-described Function (3)may be utilized instead of Function (2).

Now, operation of the access monitoring module 60 will be described inmore concrete manner.

Initially, the access monitoring module 60 monitors the status of theapplication (process) accessing the file. When the application accessesthe copyright material data, the access monitoring module 60 acquiresinherent information of the application. For example, the accessmonitoring module 60 activates a wrapper module of a kernel module ofthe operating system 50 so as to detect a file access API call of theapplication, whereby a process ID of the application as a source ofcalling operation. In addition to the process ID, the access monitoringmodule 60 may acquire information of the application name, the detectedtime and so on. Further, the access monitoring module 60 acquires a nameof a file containing the copyright material data. Then, the acquiredinherent information for the application and the name of the filecontaining the copyright material data are registered in the managementtable 61 so that the inherent information and the name of the file areassociated with each other (step S16). As has been described above, thefile name is composed of a series of characters containing the name oflogical drive in which the copyright material data is stored.

At step S15, when determination is made on whether the file as a targetof reading operation is the copyright material data or not, if it isrecognized in advance that the file system utilized as the logical drivehaving the file saved is an encryption file system, then it becomespermissible for the processing to regard the targeted file of thereading operation as the copyright material data without any otherconfirmation procedure. In this case, if the encryption file system issetting a cryptography attribute for a file or a folder, thedetermination may be made on whether or not the file is the copyrightmaterial data by using the cryptography attribute.

Further, at step S15, when determination is made on whether the file isthe copyright material data or not, the access monitoring module 60 mayhook not only the information obtained from the file system but also theauthentication procedure upon connecting the system to a server as isdone in a situation of Web browser, a streaming video reproductionapplication or the like. When a streaming video reproduction applicationis activated, the application sometimes creates an intermediate file forvideo reproduction in a storage unit. In particular, in a situationwhere copyright material data is subjected to a streaming processing,unlike in a situation of download processing, it is presupposed that thecopyright material is not stored in a storage unit. Therefore, if theaccess monitoring module 60 hooks the authentication procedure with thestreaming video server as described above, then an encipheringprocessing described later on becomes also applicable to theintermediate file.

On the other hand, the access monitoring module 60 acquires the filename thereof when the application as a target of registration creates anew file, and registers the file name in the management table 61 as atarget file of encryption. If the logical drive in which the target fileof encryption is stored is same as the logical drive in which thecopyright material data accessed by the application as a target ofregistration is stored (YES route at step S20), the file name need notbe registered in the management table 61 by the following reasons.

One of the reasons is that if the logical drive in which the target fileof encryption is stored is same as the logical drive (storage 10) inwhich the copyright material data is stored, then the target file ofencryption is automatically enciphered by the encryption file system 11and stored in the logical drive. The other of the reasons is that if thetarget file of encryption is stored in the logical drive (storage unit10) in which the copyright material data is stored, which fact meansthat the data can be protected from being flowed out therefrom.

Conversely, based on the above reasons, the name of the target file ofencryption may be partly changed by using the aforesaid Function (3) atstep S21 so that the target file of encryption is stored in the logicaldrive in which the copyright material data is stored. This scheme willalso be effective in protecting the copyright material data. Forexample, when the application tries to access the target file ofencryption, this access is hooked and the character series indicative ofthe logical drive name corresponding to the file name is changed so thatthe character series is replaced with the name of the logical drive inwhich the copyright material data is stored. This scheme is effectivewhen it is requested for the file to be prohibited from being writteninto a logical drive which is different from that of the copyrightmaterial.

When the application executing module 40 terminates the operation of theapplication as a target of registration, the access monitoring module 60erases all the data concerning the application from the management table61. That is, the information inherent to the application, the file nameof the copyright material data, the name of the target file ofencryption and so on are removed from the management table 61.

Next, the processing sequence of the filtering module 70 employed in thedata management system as the first embodiment will be described withreference to the flowchart (steps S31 to S45) shown in FIG. 3.

The filtering module 70 carries out enciphering and deciphering withreference to the management table 61 in response to the file access fromthe application.

The operation thereof will be described with reference to the flowchartshown in FIG. 3. Initially, the filtering module 70 caries out aninitial setting (step S31). Thereafter, it is examined whether thecalling (Call) of the file system function or the returning (Return)from the file system function is made or not (step S32). If it isdetermined that the calling of the file system function is made (YESroute of step S32), then it is examined whether or not the file is atarget of encryption and the encryption function is brought into a validmode by the switching module 72 (step S33).

If it is confirmed that the file is a target of encryption and theencryption function is brought into a valid mode by the switching module72 (YES route of step S33), then it is examined whether the access tothe file is a writing access or not (step S34).

If it is determined that the access to the file is the writing access(YES route of step S34), then reference is made to the management table61 to acquire the inherent information for the application (process ID),an encryption key is created based on the process ID (step S35), anddata as a target of writing is enciphered by using the encryption key(step S36). Thereafter, the following processing job is transferred tothe file system (i.e., file system function CALL; step S37), and theprocessing returns to step S32.

If it is determined that the access to the file is not the writingaccess (NO route of step S34), then it is examined whether the access isa reading access or not (step S38).

If it is confirmed that the access to the file is the reading access(YES route of step S38), then reference is made to the management table61 to determine whether it is necessary to change the file name or not(step S39).

If it is determined that the file name should be changed (YES route ofstep S39), then the file name is changed (step S40). Thereafter, thefollowing processing job is transferred to the file system (step S37),and the processing returns to step S32.

If the file is not one as a target of encryption, or the encryptionfunction is not brought into a valid mode by the switching module 72 (NOroute of step S33), then the processing immediately proceeds to stepS37. Further, if the access to the file as a target of encryption is nota reading access (NO route at step S38), or it is unnecessary to changethe file name (NO route at step S39), the processing also immediatelyproceeds to step S37.

On the other hand, if the processing returns from the file systemfunction (NO route of step S32), then it is examined whether or not thefile is a target of encryption and the encryption function is broughtinto a valid mode by the switching module 72 (step S41).

If it is confirmed that the file is a target of encryption and theencryption function is brought into a valid mode by the switching module72 (YES route of step S41), then it is examined whether the access tothe file is a reading access or not (step S42).

If it is determined that the access to the file is the reading access(YES route of step S42), then reference is made to the management table61 to acquire the inherent information for the application (process ID),an encryption key is created based on the process ID (step S43), anddata as a target of reading is deciphered by using the encryption key(step S44). Thereafter, the following processing job is transferred tothe calling source of the file system function (i.e., RETURN; step S45),and the processing returns to step S32.

If the file is not one as a target of encryption, or the encryptionfunction is not brought into a valid mode by the switching module 72 (NOroute of step S41), then the processing immediately proceeds to stepS45. Further, if the access to the file as a target of encryption is nota reading access (NO route at step S42), the processing also immediatelyproceeds to step S45.

Now, the operation of the filtering module 70 will be described in amore concrete manner.

As described above, the encryption key is created by using informationinherent to the application registered in the management table 61. Forexample, one of possible schemes is that the process ID assigned by theoperating system 50 is utilized as described above.

If a file is enciphered with the process ID as an encryption key, thefile can not be deciphered when another application as a target ofregistration tries to access the file. Because this application uses anencryption key different from the process ID. Moreover, even if the sameapplication accesses the enciphered file as another trial, theenciphered file can also not be deciphered because the process IDcreated as an encryption key and utilized in this trial is differentfrom the original process ID.

However, two applications can occasionally have the same process ID andan enciphered file can be unintentionally deciphered by accesses of thedifferent registration target applications. In order to protect theenciphered file from being deciphered unintentionally in the above case,it is effective for the encryption key to be made inclusive of timeinformation or the like together with the process ID. For example, theencryption key may be made inclusive of time information indicating atime when the access monitoring module 60 detects an access which ismade by a registration target application to the copyright material.Further, the encryption key may be made inclusive of time informationindicating a time when the access monitoring module 60 detects a filecreation which is made by a registration target application. In thisway, the encryption key is made inclusive of any time information toprohibit an identical encryption key creation. Because the operatingsystem 50 never assigns an identical process ID to two or more processesat a time on the same system.

The encryption keys are reserved only within the filtering module 70 andhence they are not transmitted through a communication path or reservedin the storage units 10 and 20. Therefore, the encryption keys seldomsuffers from a risk of theft. However, some operating systems allow auser to acquire a process ID in a relatively easy manner. If it isrequested to ensure the protection of the encryption key, a work key,which is a pseudo-random number calculated on the basis of theabove-described inherent information for the application, may beintroduced in the encryption process.

As for an encryption algorithm for the data, since a file is handled asa byte series in an ordinary case, a block encryption system isappropriate.

The filtering module 70 hooks a file access from the operating system50, whereby deciphering or enciphering is effected on the file (step S34or S44). If the file access is a writing access, then the data (file)transferred by way of the operating system 50 is enciphered as describedabove and thereafter the resulting file is transferred to the filesystem 21. If the access is a reading access, the enciphered datatransferred from the file system 21 is deciphered and the resulting fileis transferred to the operating system 50.

Meanwhile, if a file as a target of encryption is created in a logicaldrive (or storage medium) identical to a logical drive (or storagemedium) in which the copyright material registered in the managementtable 61 is stored, then the filtering module 70 becomes free from atask of enciphering or deciphering the encryption target file when theencryption file system is a particular type of one or an encryption filesystem is one which allows a cryptography attribute to be set for eachfile or folder.

Further, if a person such as an author himself or herself or a personwho is licensed by the author of the copyright material creates asecondary copyright material such as when he or she edits the originalcopyright material, then the enciphering function and/or decipheringfunction of the filtering module 70 shall be made invalid.

To this end, according to the present embodiment, the filtering module70 responds to a predetermined type of password entry so that thefiltering module 70 is brought into an invalid mode in the encipheringfunction and/or deciphering function.

That is, when a user wants to change the mode of enciphering and/ordeciphering of the filtering module 70 between the invalid mode and thevalid mode, the user enters a password to the authentication module 71.The authentication module 71 compares the password inputted by the userwith a corresponding password of the user registered in advance. If bothof the passwords are coincident with each other, then the user enteringthe password is authorized. The switching module 72 changes the mode ofthe filtering module 70 from the valid status into the invalid statusonly when the authentication module 71 successfully carries out theauthentication process to authorize the user entering the password.

As described above, according to the data management system of the firstembodiment of the present invention, when an application accessescontents stored in the storage units 10 and 20 having an encryptionfunction, the access monitoring module 60 monitors the status of accessso that the status of access is placed under management of the accessmonitoring module 60 at each application (process). Thus, the contentsread and utilized by the application are enciphered and/or deciphered bythe filtering module 70 by using the process ID serving as inherentinformation of the application.

When the application utilizes the copyright material data which areenciphered by the encryption file system 11 and stored in the storage10, it is necessary for the enciphered data to be once deciphered. Thus,the deciphered copyright material can be involved in a group of filescreated by the application. Therefore, according to the presentembodiment, at least when the application accesses the encipheredcopyright material, the access monitoring module 60 registers theinherent information of the application and the name of file which theapplication tries to create newly, in the management table 61. In thisway, when the application tries to store a file not in the storage unit10 serving as a reading source and having an encryption function but inthe storage unit 20 having no encryption function, the filtering module70 will not miss the enciphering process for the file.

According to the above arrangement, even if the user is placed under anenvironment where the storage unit 20 having no encryption function andthe storage unit 10 having an encryption function are utilized in amixed fashion, and the user drives the data management system in such amanner that the application reads the enciphered contents (copyrightmaterial) stored in the storage unit 10 having an encryption functionand temporarily stores the contents as a new file in the storage unit 20having no encryption function, the following advantages can be obtained.That is, the copyright concerning the material can be comfortablyutilized by an authorized user, i.e., the copyright can be free fromunreasonable restriction, the copyright of the contents released fromencryption can be reliably protected, and great contribution can beexpected to the performance improvement in the data management system.

In other words, when digitized copyright material data (digitalcontents) is stored in the storage unit 20 having no encryptionfunction, the digitized copyright material data is once enciphered andthereafter stored in the storage unit 20. Therefore, the copyright ofthe material data can be effectively protected from a copyrightinfringement which can be brought about when the user unintentionallytransfers the copyright material data to a third party who isunauthorized in executing the copyright. Moreover, if a malicious persontries to detach the storage unit 20 from the system and open the filecontaining the copyright material data, this person will surely fail inobtaining meaningful data because the data are fundamentally composed ofa ciphertext. Thus, the copyright of the material data is effectivelyprotected from infringement.

When the application creates a new file in the storage units 10 and 20which are identical to those from which the application reads materialdata, and stores the contents in the newly created file, the contentsare written in accordance with a file system which is arranged at eachstorage unit 10, 20. That is, if the application accesses contentsstored in a file which are originally not enciphered, then the contentsare written into the storage unit 20 without undergoing the encipheringprocess. On the other hand, if the application reads contents from anencryption file of a logical drive placed under management of theencryption file system 11, creates a new file other than the source ofreading, and stores the contents (copyright material) in the newlycreated file, then the contents (file) are enciphered by using inherentinformation of the application (process ID). Therefore, only theapplication having created the file is allowed to decipher the contents(file) and utilize the same until the application terminates theprocessing.

In this case, one of recommendable arrangement is that dynamicallydetermined information such as the process ID assigned by the operatingsystem 50 is utilized as inherent information for the application, andthis information is utilized for enciphering the contents. With thisarrangement, even if the application identical to the applicationactivated upon enciphering the contents is activated for deciphering thecontents, the contents will be resistant to the deciphering processbecause of the difference in timing of activation. Accordingly, datadeciphered by means of the file created in the storage unit 20 having noencryption function will not go into a transaction process with ease,with the result that the copyright can be more reliably protected frominfringement.

Further, the data management system may be arranged so that thefiltering module 70 is switched from the valid mode to the invalid modein its operation only when the user authentication is successfullycarried out, and the copyright holder himself or herself or a personlicensed by the copyright holder (e.g., a person creating a secondarycopyright material by editing the original material) are registered inadvance in the data management system. With this arrangement, thecopyright holder himself or herself or the person licensed by thecopyright holder can make the filtering module 70 invalid in itsoperation (process of enciphering or deciphering). Thus, the editingwork or the like will not suffer from unreasonable restriction, thecopyright will be free from restriction upon executing the copyright,with the result that it becomes possible to avoid copyrightinfringement.

Further, according to the arrangement of the present embodiment, thestorage unit 10 (logical drive #S0) has a cryptography attributedetermined at each of files or folders containing contents, the contentsare enciphered at each of the files or folders in advance, andthereafter the resulting contents (copyright material) are stored in thestorage unit 10 under the management of the encryption file system 11.Alternatively, the file system as a whole is enciphered and theresulting contents (copyright material) are stored in the storage unit10 under the management of the encryption file system 11. In this way,the digitized copyright material are once enciphered and thereafterstored in the storage unit 10. Therefore, the copyright of the materialdata can be effectively protected from a copyright infringement whichcan be brought about when the user unintentionally transfers thecopyright material data to a third party who is unauthorized inexecuting the copyright. Moreover, if a malicious person tries to detachthe storage unit 10 from the system and open the file containing thecopyright material data, this person will surely fail in obtainingmeaningful data because the data are fundamentally composed of aciphertext. Thus, the copyright of the material data is effectivelyprotected from infringement.

Furthermore, according to the arrangement of the present embodiment, theaforesaid Function (5) of the access monitoring module 60 is introduced,and when a file of an enciphered version is newly created, a part of thefile name or the whole of the file name is changed and the resultingfile name is registered in the management table 61, whereby thefiltering module 70 temporarily stores the newly created file in theprimary memory means as a memory file instead of the logical drive as adestination of storage. In this way, the newly created file is onceenciphered by the filtering module 70 and thereafter stored in theprimary memory means. Accordingly, if the power supply is once cut, theenciphered file stored in the primary memory means is erased, i.e., theenciphered file will not be held in the primary memory means, with theresult that the copyright of the material data is more effectivelyprotected from infringement.

FIG. 4 is a block diagram showing an arrangement of a modification ofthe data management system as the first embodiment. In FIG. 4, likeparts or substantially the same parts corresponding to those havingdescribed above are identified by the same reference numerals.Therefore, they will not be described.

In the data management system of the first embodiment illustrated inFIG. 1, description has been made on the arrangement in which a coupleof storage units 10 and 20 are provided and a single unit of logicaldrive #S0, #S1 is built in each of the storage units 10 and 20. However,as shown in FIG. 4, a single unit of storage unit (storage medium) 80may be provided instead of the couple of storage units 10 and 20, thestorage unit 80 may be arranged to have a plurality of partitions (inthe case of FIG. 4, there are two partitions), and these partitions arearranged to serve as logical drives #P0, #P1, respectively.

In this case, the logical drive #P0 is placed under the management ofthe encryption file system 11 and functions as a storage medium havingan encryption function (corresponding to the logical drive #S0 of FIG.1). Conversely, the logical drive #P1 is placed under the management ofthe file system 21 and functions as a storage medium having noencryption function (corresponding to the logical drive #S1 of FIG. 1).

Also in this case, the present invention can be applied to themodification in a manner similar to that of the above-described firstembodiment.

FIG. 5 is a block diagram showing an arrangement of the data managementsystem as a second embodiment of the present invention. As shown in FIG.5, the data management system as the second embodiment is arrangedsimilarly to that of the first embodiment. However, the data managementsystem as the second embodiment consists of a data processing apparatus100 such as a general-purpose personal computer and a data recordingreproducing apparatus 200 connected to the data processing apparatus 100by way of a wired network such as a LAN (Local Area Network) or awireless network. In FIG. 5, like parts or substantially the same partscorresponding to those having described above are identified by the samereference numerals. Therefore, they will not be described.

The data processing apparatus 100 is arranged to include the storageunit 10, the encryption file system 11, the storage unit 20, the filesystem 21, the host file system 30, the application executing module 40,the operating system 50, the access monitoring module 60, the filteringmodule 70, the authenticating module 71, and the switching module 72,each of which components has been described in the description of thefirst embodiment. In addition, the data processing apparatus 100 furtherincludes a network file system 101.

The network file system 101 functions as an interface between anexternal wired network or a wireless network and the data managementsystem. Further, the network file system 101 manages a storage unit(storage medium) having no encryption function in the data recordingreproducing apparatus 200.

The data recording reproducing apparatus 200 functions as a secondstorage apparatus for storing therein contents (copyright material fileor copyright material data) enciphered by the filtering module 70. Thus,the data recording reproducing apparatus 200 substantially serves as thestorage unit 20 having no encryption function. The data processingapparatus 100 accesses the storage unit provided in the data recordingreproducing apparatus 200 through the network file system 101. Data readfrom the storage in the data recording reproducing apparatus 200 remainsa ciphertext version until the data is received by the data processingapparatus 100 through the network. The processing sequence to which thedata is subjected is similar to that of the first embodiment. Thus, itwill not be described.

As described above, according to the data management system as thesecond embodiment of the present invention, advantages similar to thoseof the first embodiment can be obtained. Moreover, even if a user triesto duplicate the data through the network by accident, there is no fearof copyright infringement.

FIG. 6 is a block diagram showing an arrangement of the data managementsystem as a third embodiment of the present invention and FIG. 7 is adiagram for explaining a scheme of exclusive control effected in thedata management system as the third embodiment.

As shown in FIG. 6, the data management system of the third embodimentalso consists of the data processing apparatus 100 such as ageneral-purpose personal computer and a data recording reproducingapparatus 300 such as a hard disk drive recorder attached to the outsideof the data processing apparatus 100. In FIGS. 6 and 7, like parts orsubstantially the same parts corresponding to those having describedabove are identified by the same reference numerals, and they will notbe described.

The data processing apparatus 100 of the third embodiment is arranged toinclude the encryption file system 11, the storage unit 20, the filesystem 21, the host file system 30, the application executing module 40,the operating system 50, the access monitoring module 60, the filteringmodule 70, the authenticating module 71, and the switching module 72,each of which components has been described in the description of thefirst embodiment. The storage unit 10 is involved in the data recordingreproducing apparatus 300 attached to the outside of the data processingapparatus 100. In other words, according to the arrangement of the thirdembodiment, the data recording reproducing apparatus 300 functions asthe first storage apparatus, including a logical drive, managed by theencryption file systems 11 and 301.

The data recording reproducing apparatus 300 is provided with theencryption file system 301 for managing the storage unit 10. As shown inFIG. 7, also in the data recording reproducing apparatus 300 of thethird embodiment, the application is activated so that the applicationaccesses a file of copyright materials stored in the storage unit 10which is managed by the encryption file system 301.

The data processing apparatus 100 and the data recording reproducingapparatus 300 are connected to each other through an external interfacesuch as of UBS (Universal Serial Bus), SCSI (Small Computer SystemInterface), IEEE (Institute of Electrical and Electronics Engineers)1394. The data processing apparatus 100 accesses the storage unit 10while effecting an exclusive control on the access of the data recordingreproducing apparatus 300 to the storage unit 10.

In the above-described second embodiment, the data processing apparatus100 accesses the storage unit of the data recording reproducingapparatus 200 through a network file system 101, so that the datarecording reproducing apparatus 200 provides file access services.However, the arrangement of the third embodiment is different from thatof the second embodiment in the following point. That is, in the thirdembodiment, the encryption file system 11 on the side of the dataprocessing apparatus 100 directly accesses the storage unit 10 of thedata recording reproducing apparatus 300. The processing sequence towhich the data is subjected is similar to that of the first embodiment.Thus, it will not be described.

In the arrangement of the third embodiment, the storage unit 10 in thedata recording reproducing apparatus 300 is accessed by both of theapplication installed in the data recording reproducing apparatus 300and the application installed in the data processing apparatus 100.Therefore, it is necessary to effect exclusive control on the accessesby both of the applications.

A scheme of the exclusive control effected in the data management systemof the third embodiment will be described with reference to FIG. 7. InFIG. 7, only a main portion of the data management system of the thirdembodiment is illustrated.

As shown in FIG. 7, the data processing apparatus 100 is provided with acontrol module 102 and the data recording reproducing apparatus 300 isprovided with a control module 302. The control modules 102 and 302 areconnected to each other through the above-described external interface.Control information (exclusive control signal) for carrying out theexclusive control is exchanged between the data processing apparatus 100and the data recording reproducing apparatus 300.

Further, as shown in FIG. 7, the data processing apparatus 100 and thedata recording reproducing apparatus 300 jointly have a data exchangechannel for exchanging information about access to the storage unit(ciphertext reading or ciphertext writing) through the above-describedexternal interface, in addition to the aforesaid data exchange channelfor exchanging the control information.

In this case, all kinds of access rights for accessing the storage unitmay be placed under the exclusive control. Alternatively, only an accessright concerning the write access may be placed under the exclusivecontrol.

According to the former scheme of the exclusive control, when one of thetwo components, i.e., the data processing apparatus 100 and the datarecording reproducing apparatus 300, is accessing the storage unit 10,any access from the other component is prohibited. Conversely, accordingto the latter scheme of the exclusive control, when one of the dataprocessing apparatus 100 and the data recording reproducing apparatus300 is making a write access to the storage unit 10, the other of thecomponents is permitted to make a read access. If the other of thecomponent tries to make a write access, the component is brought into anawaiting mode. Read access is allowed for both of the components at atime. Whenever access right is transferred from one component to theother component, contents of a cache memory provided in the encryptionfile systems 11, 301 and so on shall be wholly erased, and then the dataprocessing apparatus 100 or the data recording reproducing apparatus 300shall try to write data in the storage unit 10. Further, when one of thecomponents takes the access right, the component shall again readmanagement information of the encryption file systems 11, 301 at leastbefore writing operation is started.

As described above, according to the data management system as the thirdembodiment of the present invention, advantages similar to those of thefirst or second embodiment can be obtained.

While several embodiments and modifications have been described above,the present invention is not limited to these embodiments but variouschanges and modifications other than the above embodiments can beeffected without departing from the gist of the present invention.

For example, according to the arrangement of the several embodiments ofthe present invention, the authenticating module 71 carries outauthentication process by using a password. However, the presentinvention is not limited to such an arrangement but the authenticationprocess may be carried out by using biometric information such asfingerprints, voiceprints, iris patterns, handprints and so on.

Although a few embodiments have been shown and described, it would beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the claims and theirequivalents.

1. A data management comprising: a storage medium for storing contents;application executing means for activating an application so that theapplication accesses the contents stored in the storage medium andeffects a processing on the contents; access monitoring means formonitoring the status of access of the application to the contents byassociating inherent information for the application brought into anactivated status by the application executing means, with inherentinformation for the contents accessed by the application; filteringmeans for enciphering the contents with the inherent information for theapplication when the application under the activated status writes thecontents into the storage medium while deciphering the contents with theinherent information for the application when the application under theactivated status reads out the contents in the storage medium, and anoperating system as a software for controlling the execution of theapplication, wherein the operating system assigns identificationinformation to each process upon executing the application by theapplication executing means, and the access monitoring means utilizesthe identification information as the inherent information for theapplication, wherein the access monitoring means registers the inherentinformation for the application and the inherent information for thecontents in a management table so that the inherent information for theapplication and the inherent information for the contents are associatedwith each other, and the access monitoring means monitors the status ofaccess with the assistance of the management table, and wherein at leastone piece of logical drive is built in the storage medium and thecontents is reserved in the logical drive, a file system for managingthe logical drive is built in each of the logical drive, and at leastone file system is arranged to serve as an encryption file system whichenciphers the file system as a whole upon storing the contents in thestorage medium, wherein the access monitoring means compares a drivename of the logical drive as a destination for storing a file, which isnewly created when the application effects a processing on the contents,with a drive name of the logical drive registered in the managementtable, and if it is determined that both of the drive names disagreewith each other as the result of comparison, the access monitoring meanschanges a file name of the newly created file so that the newly createdfile is stored in the logical drive of the drive name registered in themanagement table and registers the changed file name in the managementtable, wherein when the application reads the contents stored in thelogical drive managed by the encryption file system, the accessmonitoring means registers a drive name of the logical drive containingthe contents read out by the application in the management table as theinherent information for the contents.
 2. A data management systemaccording to claim 1, wherein when the application effects a processingon the contents to create a new file, the access monitoring meansregisters a file name generated for the new file in the management tableso that the file name and the inherent information for the applicationare associated with each other.
 3. A data management system according toclaim 2, wherein the access monitoring means changes the file name ofthe new file partly or wholly, and registers the changed name in themanagement table.
 4. A data management system according to claim 1,wherein the storage medium comprises a first storage unit including thelogical drive managed by the encryption file system and a second storageunit for storing therein the contents enciphered by the filtering means.5. A data management system according to claim 4, wherein theapplication executing means, the access monitoring means, the filteringmeans and the first storage means are provided within a single unit ofdata processing apparatus, and the second storage unit is connected tothe data processing apparatus by way of a network.
 6. A data managementsystem according to claim 4, wherein the application executing means,the access monitoring means, the filtering means and the second storagemeans are provided within a single unit of data processing apparatus,and the first storage means is involved in a data recording reproducingapparatus attached outside the data processing apparatus.
 7. A datamanagement system according to claim 1, further comprising:authenticating means for carrying out authentication on a user; andswitching means for switching the mode of operation of the filteringmeans between a valid mode and an invalid mode only when theauthenticating means successfully carries out the authentication on theuser.
 8. A data management system comprising: a storage medium forstoring contents; application executing means for activating anapplication so that the application accesses the contents stored in thestorage medium and effects a processing on the contents; accessmonitoring means for monitoring the status of access of the applicationto the contents by associating inherent information for the applicationbrought into an activated status by the application executing means,with inherent information for the contents accessed by the application;filtering means for enciphering the contents with the inherentinformation for the application when the application under the activatedstatus writes the contents into the storage medium while deciphering thecontents with the inherent information for the application when theapplication under the activated status reads out the contents in thestorage medium, and an operating system as a software for controllingthe execution of the application, wherein the operating system assignsidentification information to each process upon executing theapplication by the application executing means, and the accessmonitoring means utilizes the identification information as the inherentinformation for the application, wherein the access monitoring meansregisters the inherent information for the application and the inherentinformation for the contents in a management table so that the inherentinformation for the application and the inherent information for thecontents are associated with each other, and the access monitoring meansmonitors the status of access with the assistance of the managementtable, and wherein at least one piece of logical drive is built in thestorage medium and the contents is reserved in the logical drive, a filesystem for managing the logical drive is built in each of the logicaldrive, and at least one file system is arranged to serve as anencryption file system which enciphers the file system as a whole uponstoring the contents in the storage medium, wherein the accessmonitoring means compares a drive name of the logical drive as adestination for storing a file, which is newly created when theapplication effects a processing on the contents with a drive name ofthe logical drive registered in the management table, and if it isdetermined that both of the drive names are coincident with each otheras the result of comparison, then the access monitoring means prohibitsa file name of the newly created file from being registered in themanagement table, wherein when the application reads the contents storedin the logical drive managed by the encryption file system, the accessmonitoring means registers a drive name of the logical drive containingthe contents read out by the application in the management table as theinherent information for the contents.
 9. A data management systemcomprising: a storage medium for storing contents; application executingmeans for activating an application so that the application accesses thecontents stored in the storage medium and effects a processing on thecontents; access monitoring means for monitoring the status of access ofthe application to the contents by associating inherent information forthe application brought into an activated status by the applicationexecuting means, with inherent information for the contents accessed bythe application; filtering means for enciphering the contents with theinherent information for the application when the application under theactivated status writes the contents into the storage medium whiledeciphering the contents with the inherent information for theapplication when the application under the activated status reads outthe contents in the storage medium, and an operating system as asoftware for controlling the execution of the application, wherein theoperating system assigns identification information to each process uponexecuting the application by the application executing means, and theaccess monitoring means utilizes the identification information as theinherent information for the application, wherein the access monitoringmeans registers the inherent information for the application and theinherent information for the contents in a management table so that theinherent information for the application and the inherent informationfor the contents are associated with each other, and the accessmonitoring means monitors the status of access with the assistance ofthe management table, and wherein at least one piece of logical drive isbuilt in the storage medium and the contents is reserved in the logicaldrive, a file system for managing the logical drive is built in each ofthe logical drive, and at least one file system is arranged to serve asan encryption file system which enciphers the file system as a wholeupon storing the contents in the storage medium, wherein the accessmonitoring means compares a drive name of the logical drive as adestination for storing a file, which is newly created when theapplication effects a processing on the contents, with a drive name ofthe logical drive registered in the management table, and if it isdetermined that both of the drive names disagree with each other as theresult of comparison, then the operation of the filtering means isvalidated, wherein when the application reads the contents stored in thelogical drive managed by the encryption file system, the accessmonitoring means registers a drive name of the logical drive containingthe contents read out by the application in the management table as theinherent information for the contents..
 10. A data management systemaccording to claim 9, wherein the storage medium comprises a primarystorage means which erases data stored therein upon power supply cut,and the filtering means stores an enciphered version of the newlycreated file in the primary storage means instead of the logical driveas the storage destination.